Polymer intrinsic viscosity control

ABSTRACT

A computer control system for controlling polymeric intrinsic viscosity of polyethylene terephthalate polyester during its polycondensing stages by utilizing a software system configured and interrelated with a hardware system in such a manner wherein it is capable of initiating process changes which is capable of producing a predetermined intrinsic viscosity polymer during the polycondensation reaction stages.

United States Patent 1 1 Moody, Jr; et a1.

[451 Apr. 15, 1975 POLYMER INTRINSIC VTSCOSITY CONTROL [75] lnventors: Asa Carlyle Moody, Jr., Colonial Heights; Richard George Kenward, Richmond, both of Va.; James William Shiver, Cary, N.C.

[73] Assignee: Allied Chemical Corporation, New

York, NY.

[22] Filed: Aug. 14, 1972 [21] Appl. No.: 280,710

52 us. C1 235/151.12; 260/75 R; 260/475 R; 444 1 [51 lnt. C1. G06f 15/46 [58] Field ofSearch 235/151.12, 150.1, 151.1; 340/1725; 260/75 R, 475 R, 346.1, 94.9 P, 949, 94.2, 94.3, 698, 699, 700; 444/1 [56] References Cited UNITED STATES PATENTS 3,108,094 10/1963 Morgan 235/151.12 X

3,275,809 9/1966 Tolin et a1. 235/l5l.l2 3,475,392 10/1969 McCoy et a1. 235/151.12 UX 3,594,559 7/1971 Pemberton 235/l5l.12 3,614,682 10/1971 Smith 235/l5l.12

Primary Examiner-JOSeph F. Ruggiero Attorney, Agent, or Firm-Fred L. Kelly 2 Claims, 1 Drawing Figure POLYESTER POL YMERIZA TION SYSTEM FOR PRODUCING FIBER-FORMING POLYETHYLENE TEREPI'ITI'IALA TE MEflNS FOR FEEDING AND MEANS FOR GENERATING ANAL OG SAMPLEO INPUTS MEANS FOR STORING ANALOG STORING AN TIC/PA TORY CONTROL PROGRAM -I| MINI-COMPU T ER I SAMPL ED INPUTS MEANS FOR PROCESSING ANALOG SAMPLEO INPUTS BY RELATING TO ANTICIPATORY CONTROL PROGRAM MEANS FOR GONTROLL ING POLYMER INTRINSIC VISCOSITY DURING ITS POL YCONDE'NSA T ION REACT/ON STAGES POLYMER INTRINSIC VISCOSITY CONTROL BACKGROUND OF THE INVENTION This invention relates to a computer control system for automatically controlling the preparation of a high molecular weight and high quality fiber forming poly- .mer. More particularly, it relates to a computer control system for automatically controlling the preparation of a high molecular weight and high quality polyethylene terephthalate polyester suitable for processing into fibers, films and other shaped articles. Still more particularly, this invention relates to a computer control system for automatically controlling polymeric intrinsic viscosity of a high molecular weight and high quality polyethylene terephthalate polyester during its polycondensation reaction stages suitable for processing into fibers, films and other shaped articles.

Linear polyethylene terephthalate polyester is currently produced commercially by either the ester interchange reaction between dimethyl terephthalate and ethylene glycol or the direct esterification method utilizing terephthalic acid and ethylene glycol usually in the presence of a catalyst. These processes were ini' tially described in U.S. Pat. No. 2,465,310 to Whinfield and Dickson. Other U.S. Patents such as U.S. Pat. No. 3.024.220; U.S. Pat. No. 3,050,533 and U.S. Pat. No. 3,050,548 illustrate substantial improvements of these processes over the initial disclosure by Whinfield and Dickson. Needless to say. many other improvement type patents have issued in the preparation of high quality fiber grade polyethylene terephthalatepolyester. And. indeed. many others will issue in this area of technology as this product is one of significant commercial importance.

Applicants observed that in order to prepare a high molecular weight and high quality fiber forming polymer in the most economical way. then such preparation had to be automated to a significant extent if not completely. Such. to a great extent is applicants invention.

SUMMARY OF THE INVENTION Therefore. it is a prime object of this invention to provide a computer control system for automatically controlling the preparation of a high molecular weight and high quality fiber forming polymer.

Another object of this invention is to provide a computer control system for automatically controlling the preparation ofa high molecular weight and high quality polyethylene terephthalate polyester suitable for processing into fibers, films and other shaped articles.

Another object of this invention is to provide a computer control system for automatically controlling polymeric intrinsic viscosity of a high molecular weight and high quality polyethylene tcrephthalate polyester during its polycondensation reaction stages suitable for processing into fibers. films and other shaped articles.

Still another object of this invention is to provide a computer control system for automatically controlling polymeric intrinsic viscosity ofa high molecular weight and high quality polyethylene terephthalate polyester during its polycondensation reaction stages suitable for processing into fibers, films and other shaped articles in a more economical manner.

Other objects, features and advantages of this inven- 1 tion will become more apparent from the following description when taken in conjunction with the accompanying information flow by program block schematic diagram.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic representation of a control system for polymerization of polyethylene tercphthalate polyester which employs the apparatus of this invention.

BRIEF DESCRIPTION OF THE DIAGRAMS The diagrams illustrate information flow by program in a block schematic diagram type.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION An in-line closed loop computer control system for controlling polymeric intrinsic viscosity during its polycondensing reaction stages is illustrated. Such control strategy is based on discrete monitoring of in-line Contraves (manufactured by Olkon Corporation, Stamford. Conn.) viscometers at the inlet and out of the final polycondensation reactors. Feedforward or anticipatory control and feedback algorithms are used to provide intrinsic viscosity control to within less than i 0.005 units. Schematic 1 depicts a simplified overview of how the control system operates for each reactor. The local loop direct digital controllers are designed to maintain closed loop set points for vacuum and agitator speeds of each reactor. At frequencies consistent with each reactors dynamics the Direct Digital Control Director (DDC) or software program evaluates current intrinsic viscosity. The current intrinsic viscosity is compared to a target intrinsic viscosity. New setpoints are automatically calculated for implementation by the local loop controllers. Intrinsic viscosity changes are accomplished by the local DDC controllers manipulating reactor conditions to produce a target intrinsic viscosity.

The DDC software routinely operates as a proportional plus integral plus derivative control system based on intrinsic viscosity but is also specifically designed to automatically change to rate controllers during periods of severe upset. The routine or normal controllers provide fine tuning and the achievement oft 0.005 intrinsic viscosity tolerances during normal and minor upset process operations; and, the rate mode controllers can be automatically activated when intrinsic viscosity deviates from the specified target by a previously specified error. And, control is automatically returned to the normal controllers once the process is brought back within specified error tolerances. Thus, the rate mode controllers are designed to minimize out of specification final product during severe upset conditions. Special implementations are provided as required if the current intrinsic viscosity has changed from the last evaluation interval by more than a predetermined preset intrinsic viscosity tolerance. The current tolerance is prcset at i 0.0025 intrinsic viscosity units. The DDC options provide for automatic handling of a wide range of process conditions based on predetermined criteria.

The Real Time Control system (RTC) software is a special mini monitor designed for direct digital control of manufacturing processes. The mini monitor is designed to support a PDP-ll hardware system (manufactured by Digital Equipment Corporation, Maynard, Massachusetts). The special mini monitor is also designed to support the PDP-] 1/20 central processor. an-

alog inputs and outputs, watchdog timer, contact outputs, teletype and disk. And, superimposed on the special mini monitor are applications software required to support general purpose control systems as well as specific requirements uniqueto intrinsic viscosity control.

One of the objects of this invention is accomplished by a computer controlsystem for controlling polymeric intrinsic viscosity of polyethylene terephthalate polyester during its polycondensing reaction stages comprising a software and hardware system configured and interrelated in such a manner wherein it is capable of initiating process changes which is cpable of producing a predetermined intrinsic viscosity polymer during the polycondensation reaction stages.

Another object of this invention is accomplished by a computer control system for controlling polymeric intrinsic viscosity polyethylene terephthalate polyester during its polycondensing reaction stages comprising a software and hardware system configured and interrelated in such a manner as described in Schematic 1 wherein it is capable of initiating process changes which is capable of producing a predetermined intrinsic viscosity polymer during the polycondensation reaction stages.

Another object of this invention is accomplished by a computer control system for controlling polymeric intrinsic viscosity of polyethylene terephthalate polyester during its polycondensing reaction stages comprising the steps of feeding and storing into said computer an anticipatory group of set points, generating sampled data inputs from each reactor of pressure, agitator speed. inlet and outlet melt viscosity, inlet and outlet temperature and pump speed. precessing said sampled data inputs by relating said data inputs to said anticipatory set points, and controlling said polymeric intrinsic viscosity during its polycondensing reaction stages by comparing said sampled data inputs withsaid anticipatory set points and making changes to the process based upon any differences between said set points and said sampled data to bring the intrinsic viscosity to within predetermined limits of said set points.

And, still another object of this invention is accomplished by a real time process control computer apparatus for controlling polymeric intrinsic viscosity of polyethylene terephthalate polyester during its polycondensing reaction stages comprising a mini computer, the configurations of which consist of a central processor, a multiple word disk, a teletype, analog inputs, analog outputs. a real time clock. contact closures and a watchdog timer, feeding and storing means for feeding and storing an anticipatory control program in said mini computer, generating means for generating analog sampled inputs of physical representations of reactor pressure. agitator speed, inlet and outlet melt viscosity, inlet and outlet temperature and pump speed, storing means for storing said analog sampled input. processing means for processing said analog sampled inputs by relating said sampled inputs to said anticipatory control program, and controlling means for controlling said polymeric intrinsic viscosity during its' invention only and are not to be considered limiting of the invention in any manner.

EXAMPLE I Forty-one and one-half pounds per hour (0.25 pound moles/hr.) of purified terephthalic acid and 23 pounds of ethylene glycol per hour (0.37 pound moles/hr.) and 0.08 pounds of diisopropylamine were continuously fed to the paddle wheel mixer where they were converted to a paste. The paste mixture was then pumped from the mixer by the feed pump to the inlet of the circulating pump. The paste mixture ,was pumped with 40 parts of recirculating mixture by the circulating pump through the multiple tube and shell heat exchanger where it was heated to 260C. After leaving the heat exchanger, the mixture entered a reactor-separator which 7 was maintained at 260C. by conventional Dowtherm heating means, and 90 psig pressure by means of an automatic vent valve. The terephthalate ester, terephthalic ester, glycol-water mixture leaving this reactor was split, with part returned to the inlet of the circulating pump where it was combined with fresh paste and part flowed to the first in a series of reactors where polycondensation took place by conventional means.

' ester polymer having an intrinsic viscosity of 0.95, after processing as illustrated in Schematic l of polycondensation, was extruded through at a temperature of 295C. and pumped through a filter distribution plate to a 192 hole spinnerette. The spin pot design allows uniform flow and heating, thus giving intimate control. The filter distribution plate is so arranged and designed as to give uniform melt temperature control through shearing and substantially homogeneous polymer exiting the spinnerette through control of pressure.

The supervisory DDC system superimposed upon this polyethylene terephthalate polyester process is illustrated in Schematic 1. Upon sampling of the polyester polymer upon exiting the spinnerette the intrinsic viscosity in 60 percent phenol40 percent tetrachloroethane mixture 0.92, carboxyl end groups 16 equivalents per IOYgrams, and the melting point of 256C. as determined on :1 Differential Thermal Analyzer, using a heating rate of 4C. per minute. Samples showed that the effluent of the first reactor was 96.5% esterified.

A throughput rate of 45 pounds per hour is maintained at the inlet gear pump pressure of 800 psi and an outlet pressure of 7500 maximum. The extruded filaments are passed through a heated sleeve at a temperature rangeof from 480C. at the uppermost edge to 240C. at the lowermost edge. Upon exiting the heated sleeve, the filaments are quenched by air at 75F. and percent Relative Humidity blown against them at a right angle to the direction of the yarn movement. Following quenching, the filaments are lubricated by pas- I sage over a rotating finish roll and are converged below the roll by use of a guide. From the convergence point, the yarn bundle passes through a yarn pretensioning roll system. then over a forwarding roll system maintained at ambient room temperature and operating at 1391.] feet per minute. The yarn bundle is then fed through the draw point localizer zone wherein the hot fluid (steam) temperature is 450C. and the pressure is 122 psig and the yarn exiting temperature of 165C. The yarn then passes around heated draw rolls which are maintained at a temperature of 130C. and operating at a surface speed of 8198 feet per minute. The yarn .bundle is then allowed to relax at a constant tension prior to being wound up by passing the yarn over a sec- TABLE I Tensile Fiber Tenacity Elongation Toughness Modulus Thermal Sample l.V. Denier (gpd) at break lgpd) B.Q.l.* Shrinkage A 0.9] 1295 9.4 21.0 l.l2 l 2.3 Control 0.89 i310 8.9 13.8 0.65 I I0 200 9.0

Br 0. l. (Beaming Quality Index) Defects (broken filaments. strip hacks. nnhs. etc.) per million \nrds in beaming. Said B.Q.l. tested on an lfltru Yarn lnspeelor. Model 1007. Serial 2594. l.imll Corporation. Mineola. Ne York. Major sensitivity set at 4.0): Minor sensitivi! set at 31)).

I f-I'P ZILVISORY nae sgsren Schematic 1 11-301 Inputs Agitator Speed Inlet Melt Viscosity Inlet Temperature Exit: Melt Viscosity Exit Temperature Agitator Speed Melt Viscosity viscometer Temp.

Pump Speed Fecdfomartd R-Ir iz-v.

Fcedfonvard l -5;,

" 1 Feedback Viscomrtcr Fe dback Spin R-lll f I i Feedback R401 L; ilsc zeterl DI JC Local Loops f Vacuum Vacuum Vacuum Feedt'orward Agitator Speed Agitator Speed Agitator Speed Second Level Supervt so rQ tgg Target Specified Viscosity at Each Reactor Operator fio miunlcatlons And Process Fail Safe The following index is illustrative of the various control features. namely Supplements l-lV and Table l (Summary Control Features) and followed by the operational details thereof.

0nd heated roll system controlled at a surface temperature of C. and surface speed of 7813 feet per minute. The yarn is then wound up.

Supplement 1 Section A. Program Descriptions Process Control Mini Monitor Soft and Hard Limit Checking Program Trend Log Program Demand Log Program intrinsic Viscosity Calculator Program Supervisory Director for Direct Digital Control System Utility Programs A. Disk Utility Program B. Data Generator Program Section B. Operators Console Program Introduction & Definition of Terms Demand and Change Functions Console Validity Checks Computer Controlled Switching Alarm System Section C. Process Variable Calibration System l. Full Instrument Calibrations 2. Operator Calibrations Supplement ll l. Overall Software System Flow Sheet Overall Core Memory Layout Detail Description of Fixed Core Address Table Core Data Tables Disk File Layout and Definitions Supplement lll Section A. Computer System Hardware l. Hardware System Configuration Process Operators Console Hardware Interrupt Level Assignments Analog Input Assignments Analog Output Assignments Watchdog Timer and Digital Output Contact Section B. Direct Digital Control Hardware 1. Schematic Reactor Pressure Loops 2. Schematic Reactor Agitator Speed Loops 3. Signal Levels and Transducers Supplement lV Section A. Calculation of Intrinsic Viscosity B. Direct Digital Control Algorithm C. Digital Filter D. Example ofDDC Tuning SUPPLEMENT l Section A Program Descriptions Gui-{Auto l. Process Control Mini Monitor The mini monitor developed is a special purpose monitor designed to support direct digital control of manufacturing processes. it is not a general purpose real time monitor in the classic sense, varying not in functional differences but in user approach to support functions. The software monitor is designed to support the hardware configuration outlined in Supplement lll, Section A.l.

System design criteria revolves around the following concepts:

1. Specific real time events must be handled at frequencies consistent with process and hardware requirements. Events such as analog input, PID controllers, real time clock support, outputs, digital filtering, alarms, and interrupt requirements are handled in the first modules of the monitor. In general. the initial software modules are designed to handle time dependent hardware, software and process operations. 7

2. Many real time events may be delayed and executed central processor time permits. These events are in real time and must be overlapped with other process control requirements but are 5 not necessarily time dependent.

3. System l/O must be completely overlapped, subject to hardware, software and process priorities, in such a manner as to facilitate efficient use of central processor cycle time. Background and foreground proeessing is supported.

4. The system must be designed to control itself and operate without intervention. Process operations must be completely controllable by operator communications.

The first major time dependent support module is the interrupt servicing routine for the real time clock. The clock supporting routine is the heart of the time dependent operations. The function of the clock routine is to keep track of real time and support the options for running the real time scheduler. In addition, housekeeping is accomplished as required the time dependent operations may interrupt the non-time dependent operations in variable core.

The real time scheduler provides executive control for running analog inputs sampling, analog outputs, audio alarms, digital filtering and hard limit checking of control variables. The scheduler supports up to seven, second interval, operations and up to 13 additional minute scheduled operations. The user may specify any even multiple second or minute for each unique module to be scheduled. Encompassed within the overall control logic of the scheduler is the analog input driver used to sample pro- LII 4 digitally filter raw analog input data. This is accomplished by a numerical approximation to a first order lag filter. Filter details are discussed in Supplement lV, Section C. The third portion of analog input module is to limit check all control variables against a specified set of lower and upper hard limits. Hardcopy messages and audio alarms are activated by this portion of the system upon violation of the preset limits.

The third major module run by the scheduler is the analog output driver and its process control subcomponents. The functions of this module are to maintain DDC error controller history, calculate new set point adjustments for the DDC controllers by solving the velocity formof proportional, plus integral, plus derivitive mode control equations. In addition, it supplies the analog to digital converters with appropriate data for maintaining process conditions on the three reactors by direct interface to control values. PID details are found in the Supplement lV, Section B.

Three of. the potential seven events have been implemented on this system. The scheduler maintains master control of the time dependent events. The user has considerable flexibility in controlling the frequency of execution of all subcomponents of the scheduler. Second interval events, or time dependent operations, are executed immediately. Minute operations are placed in a queue table for execution as time permits. The nontime dependent portion of this scheduler is designed to cess variables at specified intervals. Each unique I provide linkage for programs residing on the RF-ll disk drive. As time permits the scheduler would call the appropriate program from disk into variable core and execute the program in the background mode.

The second part of the mini monitor is designed to handle operations which may be delayed and executed as time permits. This portion of the real time system is responsible for the following system operations: 1 Execute programs in variable core (background) by servicing the queueing table; (2) Output to the teletype all hardware and system error messages; (3) Take data from the disk buffer and output it to the teletype; (4) Run the operations console program from the disk; (5) Handle all disk I/o requests which may be data or programs; (6) Establish need to allow console priority changes, ie all changes to protected areas of core which would affect process control functions, and (7) Run events 1-6 in such a manner as to not conflict with each other or degrade the time dependent operations.

Final portions of the executive consists of interrupt service routines for each of the hardware devices. These include the real time clock, disk, teletype I/o, watchdog timer. and digital outputs.

Expansion of the mini monitor would be relatively simple with respect to addition of control functions or new hardware devices. The usual programming efforts would be required to add further applications programs beyond those encompassed by the system.

The only programming limitations imposed by the special purpose mini monitor is that programs which reside on the disk and are executed in variable core (background) must begin with an executable statement and end with a RTS PC instruction. Secondly, disk resident programs must not manipulate cpu priority; this is taken care of by the mini monitor. A list of programmed error codes is shown in Table A. l l. Operating procedures for generating a new resident system load module as shown in FIG. I.8.A.l.

TABLE I order to accomplish this, the program converts the filtered analog input to engineering units and then proceeds to check variable hard upper and lower limits. Ifa variable is outside this range, it automatically takes the variable out of service. If it is within the specified hard limits it proceeds to check the soft limits of each variable. There is no actual effect on the control system for soft limit violations. other than the normal operator error messages. The normal execution interval is 3 minutes to 5 minutes as set but may vary depending upon the requirements. Hard copy of all limit violations is provided with respect to variable number, date, time and actual value of the variable. A typical sample of teletype output is shown in FIG. A.2.l. The figure shows ASR- messages printed to the control room operator on limit violations. Audio alarms are not activated by the soft limit check program. Audio alarms are reserved for the hard limit violations on control variables.

3. Trend Log The trend log is a disk resident program automatically executed by the mini monitor at specified minute intervals. The functions of the trend log are: (1) provide data logging facilities and (2) provide a basis for analyzing process dynamics. The trend log gives the current values in engineering units of all variables with the exception of controller outputs which are used only for switching to computer control. An example of trend log output is shown in exhibit A3. I The trend log is loaded to the disk by the disk utility and is called TL in the disk dictionary. The process operator has the ability to start or stop the trend log via the console using functions F33 and F34. respectively.

4. Demand Log Program The demand log functions are identical to the trend SUMMARY CONTROL FEATURES Process Operators Console First Level DDC System Second Level DDC Director Conversational Status and Inquiry Operator Control of Process Operator Initiated Process Changes Individual Variable Status Trend Log Process Response/Tracking Target Specified Intrinsic Viscosity Hard Copy All Operator Actions Manual-to-AutomaticDDC Switching Variables Audio/Visual Alarms Error Alert Conditions Special Instrumentation Functions Operator Calibration Checks On-Line Instrument Calibrations Instrument Engineer Checks Proportional Integral Derivitlve Modes Maintain Local Loop Set Points Special Control Engineer Functions Change DDC Controller PlDs Specify Hard Limits Specify Soft Limits Sci: Detailed Process Operators Console Summary 2. Soft and Hard Limit Checking Program The limit checking program is a disk resident program whose two character name SA is one which is equated to a resident system minute inverval slot.

The resident system automatically brings the limit program into core for execution at an interval spec ified by the user. The function of this program is to check the current status of each input variable. In

Support PDP-l l Hardware Sample Process Variables First Order Digital Filter Hard Limit Check Control Hard Copy on Exceptions Direct Digital Control Loops Feedforward Control R2()l Feedforward Control R-30l Feedfonvard Control R-40l Feedback Control R20l Feedback Control R-30l Feedback Control R-4()l Target Specified I.\'. at Reactor Rate Mode Controllers Proportional Integral Derivitive Control Modes Automatic Mode Switching Special Implementations Communication to First Level Hard Copy of Process Changes Soft Limit Checking Hard Copy of Limit Violations 1 1 utility. lts dictionary name is DL. It is accessed by the console modules by putting the name DL on the resident system queue table. 5. I. V. Calculator Program and Statistical l. V. Averages The function of the l.V. calculator program is to provide updated l.V. values for all reactors. The values are used by the master supervisory DDC control program to initiate l.V. control. Therefore, it must be executed at an interval (min.) equal to the smallest frequency at which the master control program runs. It must also have priority (i.e., run before) the master control program in order to provide accurate l.V. data.

The second function of l.V. calculator program is to calculate all statistical parameters concerning reactor performance. The program maintains a running average and 2 sigma limits for the 3 final reactors. Summary reports are outputted by console options. Historical data is automatically reset at midnight by the date change program.

The program is loaded to the disk at system generation time by the disk utility. lts dictionary name is HL. Once the system is activated. it will continue to run at the specified minute inverral. There is no output associated with this program. its only function is to update the l.V. and statistical data tables. Details on l.V. calculation and statistical formula are shown in Supplement lV-A.

6. Supervisory Director for DDC Controllers The Supervisory Director program is responsible for maintaining target specified intrinsic viscosities at the outlets of polyeondensation reactors, R-l, R-l and R-l. ln-line measurement of melt viscosity is obtained by direct input from a modified Contraves viscometer. The intrinsic viscosity is calculated from the relation between melt viscosity and temperature. The Supervisor calculates new set points based on the current viscosity and its relation to operator specified target viscosity.

The Supervisory Director uses feedforward and modified feedback control algorithms to maintain intrinsic viseosities to i 0.005 l.V. units. Special implementations are activated based on preset l.V. error tolerance criteria. In addition, rate controllers are available for handling large process upsets. These are also activated by a preset error tolerance.

Feedforward adjustments are calculated from an algorithm of the form:

PADJ Cl *AlV. 1.

where:

PAD] Adjustment to local loop pressure set point Cl Constant based on process characteristics ALV. Change in reactor inlet viscosity since last feedforward implementation Since a distance velocity lag exists between the reactor inlet viscometer and the reactor inlet, the adjustments are placed in a delay table and implemented after an appropriate delay time.

Reactor feedback adjustments are calculated from an algorithm of the form:

and PN is calculated by one of the following algo- PN PN-1+KP (CZ-(EN-ENl/T) 3.

where:

PN. PN-l are the set points calculated at intervals N and Nl,

PAD] is the adjustment to the pressure set point.

PN-l is the set point calculated on the last entry to the supervisory control routine,

EN,EN1 EN2 are the error terms (target intrinsic viscosity current intrinsic viscosity) at intervals of N, N-l and N2 where the interval time is T,

K] is the integral time,

KD is the derivative time,

T is the time interval between execution of the supervisory routine,

PCSET is the current pressure set point,

C2 is a constant, and

KP is the rate control constant.

Equation 2 represents the normal three mode PlD control algorithm and adjustment to the pressure set points will normally be calculated by it. However, in the event of a large upset. control will be transferred to a rate control algorithm, equation 3, until the deviation from set point is returned to within some specified, l.V. value. Control will then be transferred back to the PID algorithm.

The supervisory control program is entered at a time interval specified in the resident system. The supervisor then checks to see if it is time to implement feedforward control and takes the appropriate action. The supervisor then updates the error table and calculates a new value for PN based on one of the above algorithms. It then checks for feedback implementation time and outputs an adjustment if necessary. Adjustments are transmitted to the local loop DDC controllers for implementation. All computer initiated process changes are reflected on the teletype located in the control room. A typical example of supervisor output is shown in H0. A.6.l. The supervisory control program has the additional facility of being able to implement feedback control if the intrinsic viscosity has varied by more than a specified amount since the last feedback implementation. This should set the limits of the intrinsic viscosity variation during normal operation. Normally control is geared to i 0.0025 l.V. units.

7. System Utilities System utilities, i.e. offline programs, required to get the system on stream were confined to a disk ut lity program and a data generator program.

7.A. The disk utility program has the following func- V tions:

1 Clear the RF-] 1 disk of all programs and data files.

2. Store on the disk compiled programs and data files to be executed and used by the mini monitor, and

other programs.

3. Create a master dictionary which correlates the program name and size with the actual disk location.

4. Delete an existing program or data file from the RF-l 1 disk.

The disk utility is a conversational type off line program where the operator performs the functions outline above. The utility is used only at system generation time. Operating procedures are outlined in the following section.

DISK UTILITY PROGRAM OPERATING INSTRUCTIONS I. Functions A. Zero the RF-l I completely.

8. Store programs on available RF-l 1 tracks and create an eight word dictionary. Entries are stored on track zero beginning in the second block (256 words/block) and running consecutively thereaf ter.

C. Delete existing program or data file and replace it with a new program or data file.

Program dialogue and directions are accomplished by conversational responses via the ASR-35 TELE- TYPE Options and program dialogue are discussed under operating procedures.

II. Loading Procedures The disk utility requires the following object tapes: A. Modifed floating point program with modules for Ascii-to integer conversion and other required subroutines.

B. Octal Debugging Program (ODT) with starting address at 31000 octal bytes.

C. Input/output executive supplied by DEC compiled with starting address at 25000 octal bytes.

D. Disk utility in absolute loader compiled by PAL- 11 assembler.

E. Load procedure 1. Load FPP at 7000 Set location 30=7000 Load IOX at 37500 Load ODT at 37500 Load disk utility (absolute) at 37500 Program starting address is 4042 111. Operating Procedure Completion of the steps outlined in Section 11-23 will result in teletypc output which begins the program dialogue.

DISK UTILITY PROGRAM CLEAR DISK PROGRAM TYPES Clear Disk Option Typical Console Messages and Responses I. Disk utility program I Clear Disk? Y Type III Y 2. Password Type in 662 3. *RE. DA. 1. Program now ready for command string Option 2: If the user responded with a request not to clear the disk there are two possible options either to delete a program/data file or create a new disk data file on program. The program bypasses the password response and goes directly to Step 3. The program is now ready to accept the command string which delineates programs and data tapes.

Command string is of the form:

Command, file name, data mode, record length Immediately upon completion of this command the program reads the tape via the high speed reader and performs the command operation.

Command: There are two possible commands, i.e. Read tape or data and exit.

1. Exit command (EX) program halts. Press continue switch to return to program beginning.

2. Read command (RE) command to read paper tape input via high speed reader. Read command followed by 2 character program or file name.

Modes: There are two types of modes:

Mode 0: Data tape on program (absolute form) created by PAL-ll output with a. Start Address Variable the initial entry.

Mode 1: Data tape created by the data generator program. The tape is also in absolute form.

Record Length: Record length is in decimal words and is used to read in the number of words on the tape. For programs, record length should be set to d) in order to place the entire program on disk as a continuous disk entry.

The disk utility must be restarted when loading each successive file after the first one is loaded. This is accomplished by loading 4042 and press start. Select the NO option for clearing disk and proceed with the command string for the file. All files must be loaded after all programs are loaded to the disk.

The program types out an asterisk after finishing each unit operation. Successive programs or data files can be loaded to the disk by repeating steps outlines. An example of the disk utility output is shown in exhibit A.7.1 for the entire DDC system.

7.8. Data Generator Program The data generator program is designed to create data tapes to be loaded to the RF-l l by means of the disk utility program described in Section A.7.A. Input to the data generator program can be accomplished via the ASR-35 Teletype. prepunched ASCII tape or high speed paper tape input. Based on the option selected. the data generator outputs an absolute binary tape. Data modes for ASCII. integer and floating point formats are provided. This program may be used in conjunction with the disk utility at system generation time.

DATA GENERATOR PROGRAM OPERATING INSTRUCTIONS Loading Procedure The data generator program requires the following object tapes:

A. Floating point package B. Input/output executive compiled at 15100 C. Data generator object tape compiled by PAL-ll Actual loading procedure is as follows:

. Load FPP at 20000 Set location 30=20000 Set location 32=340 Load IOX (self loading at 15100) Load data generator program (1000-15000) Load address 1000 Press start Program conversation will begin on ASR-35 Operating Procedures Completion of the loading procedures outlined in steps l-8 above will result in the following ASR-35 message.

Program types: INPUT DEVICE -Continued The operator then types as input: 1. L carriage return if his input is coming from a prepunched ASCII tape to be read in on the low speed 5 Z FPP 9'367 reader. Pre-prepared input tape must be prepared by 9 Y the editor and end with a form feed. 10 FPP 486.3

2. H carriage return if his input is coming from the H high speed paper tape reader. Prepared tapes must be prepared by the editor and end with a form feed. The 10 carriage return causes tape to read in. FIGS- 3. CTL/L, carriage return if his input is coming from the teletype keyboard. After typing carriage return the Resident System Error Messages program is ready to accept keyboard input. A form A- 5'l5 11145 feed input (CTL L) causes the data to be put to the Vilf- 01 exceeds pp h limits specified output device Taken Off COHUOI & out Of SCl'ViCC Data lines can be ASCII, integer or floating point forl 1145 mats. All lines should be ended with a carriage return, *Alarm* var. 0.5 exceeds lower hard limits line feed combination. Within a line any ASCII data is ken ff C r & Out Of Service interpreted by the math package. Any line beginning 20 C- ariz ble n C0ntr0 -0u servi e with a; will be ignored and treated as a comment only. Go In Service Off Control The decimal point is used to determine if number is All Soft nd Hard Limit Ch ck Program Messages floating point. Upper soft limit violation on variable Number 20 A typical example would be for keyboard input as Limit is 275.00000 follows: Current value is 276.49200 l. 2. 3.6. 9.367. 486.3 Tim f occurcncc This would create a data tape of the following format: 13/05 10/1 muck l 1 Upper hard limit violation on variable Number 2 2 2 Limit is 3.5000000 Current value is 3.6920000 3 Time of. occurrence FPP 12/1410/19/71 i This variable has been taken out of service Figure LAAJ.

DEM/till) LOG TIHE- 14:48

CONTROL VAZ-ilf-IZLES vrsc z SCALE 19.17 W1C 1.9 59 AGIT SPEED 44.96 VISC Z SCALE 42. 41 R-39l W1C .4828 AGIT SPEED 57.45 VISC Z SCALE 6285i R-4Gl VAC .4822 AGIT SPEED 5 4.75 VISC Z SCALE. 51.59

TA :GET minim-LES R-1I7 I-VISC .1443 IIJ/ISC TEMP 274.4 3*251 I.VISC .5252 E.VISC TEFP 265.4 R-SGI LUISC .9657 E.VI SC TEi-iP 286.5 R-4Ul I-VISC .9897 E.VISC TEI'iI 2S7. 8

MONITORED VARIABLES SIZuJ7-u":- IILET PUMP SPEED 41.30 51398-5 l (ELF-ET PUMP SPEED 40.25 81497-6 INLET PUMP SPEED 48.76 51458-5 INLET PUMP SPEED 29.64

STATUS REFDRT CONTROL. SERVECE R-20l VACUUM ON IN R-S'Z- l VACUUM OFF Iii R- lfil VACUUM ON IN R-ZEll AGIT SP OFF IN Resident System Programmed Error Codes Set ERR 02 Watchdog Timer Lapsed Not Reset Within Seconds (Computer Failure Horn Alarm Also) ERR 03 Disk Buffer Size Exceeded 2048 Words ERR 04 Starting Address Within Track 2048 For A Program On Disk ERR 05 Starting Track Address Of A Program On Disk Exceeds I28 ERR 06 Program On Disk Exceeds Maximum Size Of Variable Core ERR 07 lnvalid Operator lnput On TTY Re-enter Entire Line ERR 10 Power Failure Has Occurred ERR l l System Restart (Software) ERR 12 Spare ERR l3 Teletype lnput Occurred Done Bit Not Set ERR l4 RF-l 1 Disk Hardware Error Occurred Done Bit Not Set ERR Program Or File In Queue Not Found In Disk Dictionary FlG. l.A.6.l

srnus REPORT CONTROL. SERVZCE Continued R-Mll AGIT s? 011 111 R-Afil AGIT s? oFF 111 11-2211 use .7 011 111 11-551 7150 '1. on our 11-401 VISC z oFF our 11-251 1 .v. oFF 111 12-521 1. v. oFF- 111 17-4a1 1.11. OFF 111 11-1 17-1 .v. oFF IN 11-1 17 use :1 OFF 111 17-117 vrse fit-1P .GFF 111 12-2a1 VlSC 721-1? oFF 111 12-5171 VISC TEE-1P. oFF 111 12- 131 VISC T211? oFF OUT 3127-3 P022? 5; OFF our se-s P1112? SP oFF 0117 437-7) P1111? 51' on 0117 1188-5 PUl-El 51 OFF out 001411201 vanL-zztzs 11-1 17 VISC 7. SCALE 19. 1 1:-2:1 was 1 .759 112-17 SPEED 4 1.91 VISC 7. sex-.12 .1 11-51 v.21: 1765 AGIT SPEE 57.55 vxsc 2 52:1 .1: s1 12- 1131 W10 .4553 A611 smzzn 54.56 VISC z SCALE 5.9.7:

7.1111121 \IA IALLES 12-117 1.1/15: .1441 1.v1sc T211? 274.; 17-251 1.v1sc .521; E.VISC 721;? 267.7 1-351 1.1 .9581 E.VISC T211? 25.s 11-4a1 1.11190 .9792 15.v1sc TEN? 235.9

aciuremsn VARIALLES 91337- 12.1.13 P1111." SPEED 41 15 sues-'3 11.1.57 r1112." SPEED 40.25 31457-5 11-: 2? PUMP SPEED 49.1.1 suns-5 1111.127 Pun? SPEED 29.99

TABLE A.l.l Supervisor Output Messages A. Supervisory control summary reactor 201 Control Data Feedforward adjustment 0.0300 Feedback adjustment 0. 1000 Total adjustment 0.0700 Max. adjustment allowed 0.2000 Old setpoint L600!) New setpoint 1.6700 Target l.\". 0.5200 Current l.\. 0.5300

B. Warning Reactor 201 is out of serived Feedforward adjustment set to 0.0

C. Warning Reactor 301 is out of service Feedback adjustment set to 0.0

D. Warning Reactor 401 viscometer is below 265 degrees C Feedback adjustment set to 0.0

E. Warning Reactor 401 is at its upper soft limit further adjustment will not be made until soft limit is changed F. Warning Reactor 301 is at its lower soft limit further adjustments will not be made until soft limit is changed Figure 'I. 7.A.1

1: DISK UTILt'IY PROGRAM CLEAR DISli't. Y

PASSWORD? alt HE,C5,1 ,o

Rena, l ,0

JW fii m 4042 Restart Disk Utility Select N Option v s s L 4042 Restart Disk Utility Select N Option EX- '4: DISK UTILITY PROGRAM CLEAR DISK? J C. Start D. After completing load I. Set 30 25000 32 340 3. Load resident system binary tape by A. LD 37500 start 4. Load calibration tape by A. LD 375d start 5. To run new system LD S.A. of resident system B. Press start 6. Check new system out. When satisfied its O.K.. generate a complete load module eusing following step. 7. Load dump AB tape (no special leader) into SA of V core by:

. LD 37500 Set 15501 in data switches Press start Dump AB will stop Load l55d d in switch and start Dump AB will stop at 15502 Load 0/? device 177544 punch in switches Press continue dump AB will halt I. Set SA d) in switch press continue J. Dump AB will halt K. Set End address SA of stack 37477 L. Dump AB will now dump entire core M. Check load module to see if its OK. by load 37500Read in tape halt N. Load SA of resident system press start system should now be running.

Section B Operator's Console Program 1. Introduction and Definition of Terms Communication with the computer is achieved by data input and output on the console teletype. The console programs are designed to support specific operator and control engineer requests. The requests may be to obtain information about the current status of the process or to direct the computer to automatically change theprocess. Coded input to the ASR-35 teletype will initiate one of 30 different functions for a specific coded variable. Specific variable numbers and functions are outlined in the Process Operators Console Summary. See l.B.l.l.

The complete console program is composed of five different modules, each one supporting specific groups of functions. The modules reside on the RF-l l disk and are called into the background for execution by the resident mini monitor. The modules and their support functions are listed below:

a) Name C l Supports functions P. F0] thru F04 b) Name C 2 Supports functions F06 thru F08 c) Name C3 Supports functions Fl 3. F16 thru F23 d) Name C4 Supports functions F27 thru F34 0) Name C 5 Supports functions F35. F36. F39-F4l f) Name C6 Supports functions F 4247. F50-56 The console program accepts three types of data for-- mats:

a. Initiation format This takes the form of VXX- FYY Where XX is the variable number prefixed by a V and YY is the function number prefixed by an F. The specialized format P for panic is also recognized. ()denotes a teletype carriage return.)

b. Data Format Data is entered on the command of the system in the format NNN. NNNN where N is any numeral between and 9. The decimal point may be located anywhere in the string but accuracy is limited to 8 characters.

c. Acknowledgement Format Entries which change the systems direction must be accepted or rejected after entry. This is accomplished by typing 1. R Reject last entry or 2. A Accept last entry All entries for each format must be terminated with a teletype input carriage return 2. Demand and Change Functions The console program accepts two types of function requests:

2.] Demand function requests These requests allow the operator to obtain information about the process and do not change the system in any way. The dialogue. for example. to obtain the value of the pressure in reactor 20] would be:

VARIABLE NUMBER 1 CURRENT VALUE UNITS (Underlined characters are those output by the computer) On completion of a request the computer outputs *l indicating it is ready for further requests.

2.2 Change function requests these requests allow the operator to make a change to the system. However, before the change is executed. the computer prints out a summary of the relevant information to allow the operator to check the request.

Two types of change function requests are available and can best be illustrated with examples.

2.2.] Change functions requiring no data entry.

The dialogue to put reactor 30] on supervisory control would be:

VARIABLE NUMBER 8 PUT ON COMPUTER CONTROL ACKNOWLEDGE After the computer has printed out the request the operator will be requested to acknowledge it. i.e. either accept (A) or reject (R). Only after the operator has typed A or R and the computer has output *I will the operator know that the request has been executed.

2.2.2 Change functions requiring data input The dialogue for changing the target intrinsic viscosity for reactor 401 would be:

INPUT DATA VARIABLE NUMBER CHANGE SET POINT OLD VALUE 0.9900 ENGINEERING UNITS NEW VALUE 0.9650 ENGINEERING UNITS ACKNOWLEDGE 1.724 ENGINEERING After the computer requests data, the operator types in the new set point. The computer then outputs the old value and new value and requests acknowledgement.

LII

After execution of the function. the computer indicates its readiness to accept further requests.

3. The console program checks the validity of input information and will output or error message for an illegal entry. Thus. the dialogue for attempting to change the set point of reactor 20l viscometer temperature would be:

INVALID VARIABLE RESTART Similarly. the dialogue for an invalid function request would be:

INVALID FUNCTION RESTART The dialogue for failing to input data when required would be:

INPUT DATA DATA EXPECTED RESTART 4. Computer Control Switching to DDC The console modules are designed to provide bumpless transfer from conventional control to computer direct digital control. The procedure for placing a local loop variable on DDC is as follows:

4.l Place the conventional controller for the specific variable in the manual mode.

4.2 Input the local loop set point to the computer by using console function F06 with the appropriate variable prefix. This step may be eliminated by demanding the current stepoint and determination of whether the existing stepoint is all right.

4.3 Via the console request the appropriate variable to place on computer control using function F01 with the appropriate variable number prefix.

4.4 The computer will automatically match the computer output with that of the conventional controller. This can be verified by examination of the two horizontal meters in the control board. If they are in fact matched, the operator may proceed to step 4.5.

4.5 Switch the appropriate computer switch to the on position. These are located in the control board and labeled accordingly. At this point, the computer assumes control of this process variable and the conventional control has no effect on the process.

4.6 This procedure is repeated for each variable to be placed on control with the appropriate variable number.

In the event that it is necessary to take a particular variable off of local loop control. the following procedure must be followed;

a. The conventional controller should be in manual if it is not. put it in the manual mode.

b. Match the conventional controller output with the output of the computer by adjusting conventional controller output to line up with computer output. Visual inspection of the horizontal meters in the control board will show when they are matched.

c. Switch the appropriate computer switch from on to off. At this time the conventional controller has control of the process variable.

pervisory 5. Alarm System The overall alarm and software failsafe checks are a must in the design of computer control systems. Each component of the total system must include alarming mechanisms to either alert the process operator and/or restrict computer operations during failure conditions. The hardware alarm designated PA 50l5 and located in the control panel is activated on computerfailure or hard limit violations of specific process variables. In the event of a computer failure the audio alarm will sound and process status is locked to the last valid settings. In the event of one or many input failures. the alarm is supplemented with messages which tell the operator which process variable is in error, i.e. which variable is outside preset hard limits. When a variable violates this condition. it is automatically taken out of service and off control. Operator intervention is required to place the variable back in service and on control.

Soft limit violations of a process variable will cause messages to be printed to the teletypc specifying which variable is outside the soft limits. This is merely a warning to the operator. There is no automatic action taken against the system.

Section C Process Variable Calibration System The software calibration system is designed to: (1) Provide an on-line means of calibrating newly using instruments with the system, and (2) Provide a method for evaluating system reproducibility over long periods of time. The two functions are referred to as Full lnstrument Calibrations and Operator Calibrations Respectively.

l. Full Instrument Calibrations These console functions are normally restricted from use. The authorization features must be activated in order to proceed with full instrument calibrations. The steps for full instrument calibration are:

A. With the transducer input for the variable to be calibrated preloaded to a value which corresponds to full scale. initiate console function F- l 6 with the appropriate variable number prefix. The system will ask for input data. Input to the system is the value read by instrument personnel on their metering device in engineering units. Once the computer has completed the full scale calibration run, it will output new and old calibration data.

(PER- an Var. l-unct r APT Process Description Function Description Control. Variables 201 Vacuum 01 P Panic Break all DlJC loops 301 Vacuum 2 61 Put variable on computer control 40 Vacuum I 63 952 Take variable off computer control 201 Agitator speed 64 933 Put variable in service 301 Agitator speed 65 {64 Take variableout service 40]. Agitator speed 66 201 viscometer 7. scale 07 06 Change variable setpoint 301 viscometer scale 58 {67 Change lower soft limits 101 viscometer 7. scale 939 98 Change'upper soit limits 959 Change viscometer Calibration Slope Target Variables 1 Change Visc.- Calibration lntezlrcept' 11 Change System Time 201 Intrinsic Viscosity l3 12 Change System Date 301 intrinsic Viscosity 14 13 Accept/reject calibration- 401 Intrinsic Viscosity 1S -l6 Full scale instrument calibration** L 17 Zero scale instrument calibration='-* 18 Variable feed back calibration 19' Change lower hard limits 20 Change upper hard limits- 21 Change gain*'-'-' Monitored Variables 22 Change integral time i 23 Change derivative time 117 I 'Viscometer 7, scale l 19 27 Demand Intrinsic Viscosity 11 7 viscometer Tel-i9. 29 28 Demand lower hart.= limit 201 viscometer Temp. 21. 29 Demand upper hard limit 301 viscometer Temp. -22 3;) Demand lower soft limit 401 viscometer Temp. 23. 3]. Demand upper soft limit: 201 VAC. CI'L. ol'P 2h 32 Log & complete status VAC. CTL. o/P .25 33 Start trend log running I 401 VAC. CTL. 0/? 26 34 Stop trend log 231 Agit. Sp. CTL. o/P- 27. 3S Demand setpoint r 301 Agit. Sp. CTL. o/P 28 36 Demand PID constants 9i. Agit. Sp. C'I'L. c/P 29 37. Demand running average LV. 307 l Pump speed j I 39 39 Demand current value (Eng) 308 Pump speed 31 40 Demand current value (ADC) 407 Pump speed i 5 32 41 Demand operator calibration 403 Pump speed 33 +2 Change F.F. Implementation time u 43 Change F.I-. Delay time bt R quires Authorization to change 44 Change F.F. Algorithm constant** 45 Change LB. Implementation time-* Example: Type i A c l 46 Chang e 3 5. Rate controller K 47 'Change LB. Rate mode controller K** Change functions require operator 48 t Not implemented** s to accept (Type in A) or Reject (R) the 49 implemented request a 50 Change ErrIDecision PID F8. Ct1s.** 51 Change Err.'.tolerance EB rate controllers val- 35 D 5 201 VAC, Setpoint -52 Change Err.Fract.Automatic Mo ie Change ,l 53 Change Err.Tol.Special Control Actiou 54 Change Max.Allowable 4- Pressure 55 Change Max.Al1owab1e Pressure 56 Demand List Disk File having the computer verify the variable input. This is accomplished by using console function F-l8 and repeating the steps outlined in Step I. see exhibit C.l.2.

D. At this point the instrument engineer can accept the entire calibration, i.e. zero scale values and full scale values by simply inputting F- l 3 with the appropriate variable number prefix. The computer then automatically updates the fixed calibration tables.

2. Operator Calibrations Operator calibration checks are designed to evaluate hardware reproducibility over long range periods. This function is not restricted and may be initiated in the following manner:

A. Input to the console the appropriate variable number to be checked and the F-4l suffix. The computer will ask the operator to input data.

B. Enter the current value of the variable to be checked into the computer. Based on pre-established calibration data, the computer will output the current value of the variable in engineering units. If the input differs from the calculated value significantly, notify the foreman as hardware problems are indicated. A typical example of system input and output is shown in exhibit C.2.l. C.l.l Instrument Calibration Example V0l-Fl6 lnput Data 5.0 Variable Number 1 Full Scale Calibration Old Value 3200 ADC Units, 4.99 Eng. Units New Value 3l20 ADC Units. 5.00 Eng. Units 1 C;l.2 Variable Feedback Calibration V22 F18 Input Data 275.0 Variable Feedback Calibration Variable Number 22 Test Value 275.0 Eng. Units Feedback Value 275.] Eng. Units l C.2.l Operator Calibration V07 F41 Variable Number 7 Calibration Value 40.0 Eng. Units Supplement II 1, OVERALL SUl'TWAi-fi" SYS'I'EM FLOW SHEET Operators Process Control Console Mini Monitor I (Resident) I Teletype Variable Core Execution Of Disk Resident Program Analog l/P Field Analog O/P Process Elements Digital O/P Alarms Disk Resident RF-ll Disk Q Console Module C-l Console Module 0-2 Console System Utilities O f Line Data Generator Disk Utility Module C-3 Console Module G-4 Console Module C-S Soft & Hard Limit Checking Console Module C-6 Trend Log hi Data Change Supervisory Demand Log Control Program #1 I V Calculator) DDC Director I.V. Daily Statistical Auzn'nom:

Supplement 11 Continued Software Comgutcr Spccificnj itgs 2. Overall Core Memory Layout for DDC System PDP- ll '20 8 X.

.F. P' I Hardware Traps/Interrupt Vectors LV. Data For DDC Director/Patch Area Fixed Core Data Tables 8 Process Control Mini Monitor 10 words Variable Core Area (Loaded from RF-ll disk as required) Floating Point Subroutines Hardware/Software Processor Stack [p 37500 Absolute Loader 3. Detail Description of Fixed Core Address Tables Fixed Core Location Contents Description 400 Current Intrinsic Viscosity R-177 406 Current I.V, Reactor 201 414 Current I.V. Reactor 301 422 Current I .V. Reactor 401 424 Supplement II Continued Software Computer Specifications l'ixr-d Core l t gation Contents Description 430 Sum R-20l I.V. 'S r 432 n 434 436 Sum R-301 I .V. S 440 II 442 444 Sum R-40l' I.V. 's 446 450 452 Running Average I.V. R-20l 454 456 460 Running Average I.V. R-301 462 464 i 466 Running Average I.V. R-40l 476 5C0 1050 Unfiltered analog input s ADC units 5C2 1144 Filtered analog input values ADC units 504 1240 Soft limit tables upper and lower limits 506 1540 Hard limit tables upper and lower limits S10 2040 Analog input gain and multiplexer address 512 2134 Multiplexer address table digital-analog converters 514 21.56 Current Values for digital/analog converters 516 2200 Queue name table for programs scheduled by menitor I 520 2536 Target I.V. variable table (real numbers) 522 2250 DDC controller error history table 524 3274 PID tunning constants for local DDC controllers 526 2514 Controller set point table local loop controllers 530 2602 Local DDC controller deadband table 532 2624 On computer-in service table 534 2730 Analog input Sampling Period table (seconds) 536 0/1 Analog input calibration run indicator 1 Active 540 33 Total number analog input variables scanned 542 9 Total number control variables 54 3022 Scheduler execution intervals resident drivers 546 24 Total number events scheduled in resident system 550 3072 Table lapsed time since execution resident event 552 3500 Maximum size of variable core (words) 554 Console function save word 556 Console variable save word 560 Console pass indicator pass 1, 2 or 3 562 I Address of inco re typewriter buffer (output) 564 3142 Address of queueing table 566 Variable core busy indicator 570 RFll-disk busy indicator 572 AFC-ll analog 'uusy indicator 574 AD-ll analog output busy indicator 57-6 Current hour of day. (24 hour clock) 600 Current minute of hour 602 Analog output interval for PID algorthm 604 Month l 606 Day 610 Year 612 System error code hardware & software 614 Typewriter keyboard input buffer address 616 43 Maximum size of TTY output buffer (words) 620 Current number words in disk message buffer 622 Number jobs currently in Q table (2/job) 624 KWll-L real time clock lapsed 626 Indicator for program in V core 030 15500 Starting address of variable core Supplement 11 Continued bigg e Cum utgr Spec cations Fixed (.ore

Contents Description Analog input filter time constants table Execution interval of resident scheduler Lapsed time since execution of scheduler Current number bytes in 'l'TY output buffer Starting address of processor stack Starting address disk message buffer (track #1) Starting address of disk dictionary (track Working location stripping '[TY I/P code to ASCII Console input data save area (real word) FP format Total number analog outputs Priority functions 0 not 1 allowed Address of register save routine for V core Address of register restore routine 'for V core Disk block trans fer area size Size of each flet entry on disk Address of disk call agrument list Starting address of disk driver TTY OP buffering in progress 1 in progress Real time routines in progress 1 in progress Two word sum of ten calibration Readings analog input Address of calibration data characters inputted to TTY input buffer Total number target variables Constant l Constant 60 decimal Number 16.7 ms timer intervals lapsed Maximum variables (upper limit) includes expansion Currently implemented highest monitored variable Currently implemented lowest monitored variable Currently implemented highest target variable Currently implemented lowest target variable Currently implemented highest control variable Variable status word;

Control variable negative Target Variable zero Monitored Variable Positive Demand function status word Type 1 negative Type 2 zero Type 3 Positive Current highest demand function type 3 Current lowest demand function Type 3 Current highest demand function type 2 Current lowest demand function type 2 Current highest demand function type 1 Current lowest demand function type 1 Current highest change function type 4 Current lowest change function type 4 Current highest change function type 3 Current lowest change function type 3 Current highest change function type 2 Current lowest change function type 2 Current highest change function type 1 Change function status word (yes no Console Engr. save work area Analog to digital save area for conversion Variable no. save (ASCII) for console program Full scale ADC save area calibration Full scale Engr. units save area Real number form floating point 7 used Zero scale ADC save area calibration Zero scale Engr. units save area Real number form floating point used Supplement II Continued Fixed Core Location Conten 's DcscriptioL 1034 Time of trend log execution interval (minutes) 1036 4416 SA of DAC calibration data 1040 400 SA of current IV 5 (used by supervisory director) 1042 2424 SA of viscometer calibration data 1044 430 SA of sum of reactor I.V. 's

1046 3756 SA of sum squared of Reactor I .V.

4. :11 :1 Tables Fixed Core Data Tables Cure Core 19211 1 mm ieiltqwa si I A 1200 201 Vise. Temp. 1 21 1050 201 Vacuum Var. 1r 1 I 1202 301 Vise. Temp. 22 1052 301 Vacuum Var. i" 2 1204 401 Vise. Temp. 23 1054 401 Vacuum Var. 3 i 201 Vac CTL 0/P 24 1056 201 Agitator Speed 4 1210 301 Vac CTL. P 25 1060 301 Agitat r Speed 5 1212 401 Vac CTL O/P 26 1062 401 Agitator Speeo 11F 1214 201 Agit. Sp. C'I'L. O/P :7 1064 201 viscometer 2, if 7 1216 301 Agit Sp. CI'L. O/P 28 1066 301 viscometer "a 8 1220 401 Agit. Sp. CTL. O/P. 1r 29 1070 401 viscometer Z, 1: 9 1222 307 Pump speeds 30 1072 Expansion 1224 308 Pump Speeds 31 1074 Expansion 1226 407 Pump Speeds 32 1076 Expansion 1230 408 Pump Speeds 33 1100 117 viscometer Z 19 2 Expansion Viscome ter Temp .11 Expa'ns ion 110! 201 viscometer Temp. v71 21 1236: Expansion 1106 301 Visc. Temp. 7? 22 1110 401 Vise. Temp. -23 2f 1112 201 Vac GT1" 0/? 1; 24 I 1240 201 Vacuum Var. 1;- 1 1114- 301 Vac CTL. 0/1 25 1242 301 Vacuum 2 111.6 401 Vac. CTL. 0/1 1; 2e 4 401 Vacuum 3 1120 201 Agitator SP.CTL. 0?. #27. 12% 201 Agitator Speed 4 '4 1122 301 Agit. SP. CTL.OP.#Z&:. 1250 301 Agitat Speed 5 1124 401 Agit. SP. CTL.'O/P #29. 1252 401 Speed 6 1126 307 Pumps Speed Var. 1254 201 vscmeter 1L 7 1130 V 308 Pumps Speed Var. 1r 31 1256 I 301 viscometer 8 1132 407 Pumps Speed Var. 32 401 9 1134 s Pump Speeds Var. 33 1262 1136 Expansion 1264 I Expansion 1140 Expansion 1266 Expansion 1142 Expansion 1270 R-201 Target IV #13 1 (Real number) Filtered Analog Inputs 5 1144 201 Vacuum Var. 1 I 1276 R-301 Target I.V. #14 1145 301 Vacuum Var. 2 I 1300 (real number) 1150 401 Vacuum Var. -'/r" 3 1302 1 1152 201 Agitator SP. 4 1304 R-401 Target I.V. 15 1154 301 Agitator SP. 5 (real number) 1155 401 Agitator Speed 6 1160 201 viscometer Z 7 1152 301 viscometer Z, 8 1316 Expansion 1164 401 viscometer 7; 9 1166 Expans ion 132.0 Expans ion 1170 Expansion 1322 Expansion 1172 Expansion 1324 Expansion 1174 117 Viscome ter Z 19 1326 P Qn 1176 117 Vise. Temp. 4; 2o 1330 Expansion Supplement II Cominued SolLwzrz- C(nnpul'cr .jpM-ificntinns A. Data Tables Fixed Core Data Tables Core .gcation Description Location Description 332 Expansion 1462 Expansion 334 117 viscometer "I. 19 1464 Expansion 336 117 Visc. Temp. 4,? 20 14 5 Expansion 340 201 Visc. Temp. 21 1470 Expansion 342' 301 Vise. Temp. 22 '1472 Expansion 344 401 viscpa 1474 117 viscometer 7, 19 346 201 Vac. CTL. /1 1; 24 1476 117 v Temp 20 350 vac C 25 1500 201 Vise. Temp. 21 352 401 vac CTL. 0/0 #2 1502 301 Vise. Temp. 22 54 201 s P- 4F 27 1504 401 Vise. Temp. 4, 23 5 301 Agit- P- Z8 1506 201 Vac CTL O/P 24 Agit- 0 29 1510 301 Vac CTL 0/P 25 462 p Speed 1r 30 a 1512 401 Vac 01L 0/ 26 36 308 Pump Speed 31 151' IL 366 407 Pump Speed 32 1516 53% 22;:- gp. g 7 .3;

L p. if :72 33 :22; :2: 29 374 Ex ansion 1524 Y P pee J 30 I p I 308 Pump Speed 1 31 376 Expansion 1526 407 P Speed .1;- 3 Unpcr Soft Limits 1530 408 Pump Spead 33 0 1532 Expansion L400 201 Vacuum Var. 1 1534 1402 301 Vacuum 2 1536 Expansion 1404 401 Vacuum 3 140s 201Agit. Speed 4 w 1410 301 Agit. Speed 5 6 1412 401 Agit. Speed 6 1542 201 Vacuum 1 L414 201 viscometer 7. Scale 4F 7 1544 301 vacuum van 2 [416 301 Vise. 7. Scale 1546 401 vafuum 3 [.420 401 Visc. 7. Scale 9 9 Agltawr Speed 4 L422 Expansion 1550 301 Agitator Speed 5 L424 Expansion 4 5 401 Agitator Speed 1;- 6 L426 Expansion 1554 4 201 viscometer 7. Scale i'r 7 L430 R 201 Target v 13 v 1556 301 viscometer Z Scale l" 8 432 Real number 1560 401 viscometer 7. Scale 9 L434 1562 Expansion :223 11-301 Targ t 1v. 14 22 fig jf Real Number p nslon 1570 201 Target IV. Var. 1'3 R-401 Target IV. 15 1572 (real number) [445 Real Number 1574 1450 1576 301 Target Iv. v 14 Expansion 1600 (real number) Expansion 1502 23 Expansim 1604 401 Target IV. 1s Expansion 1606 (real number) 1744 R-401 Target 1v. 174 Real number 1615 Expansion 1620 Expansion 1750 1622 Expansion 1752 Expanslion 167/1 Expansion 1754 Expanszion 1626 Expansion 1756 P 1630 Expansion 1760 Expans%n 1632 Expansion 1762 Expansion 1054 117 viscometer 7, 19 1764 1636 117 viscometer Temp. 20 Expanslfon 1640 201 Visc. Temp. 21 1 lamp 22 1774 ,I 117 viscometer Z 19 L (4 401 VlSC. Temp. Jr 23 4 L646 201 Vac CTL O/P 1 24 1776 117 vlsc Temp {r 20 2000 201 Visc. Temp. 21 .650 301 Vac GT1. 0/? 25 2002 301 Vise. Temp. 22 .652 401 Vac CTL O/P 26 2004 401 viscometer Temp. 23

.654 201 Agit. Sp. CTL O/P 27 2006 201 Vac CTL 0/1 24 

1. IN A POLYMERIZATION SYSTEM FOR PRODUCING FIBER-FORMING POLYETHYLENE TEREPHTHALATE POLYESTER, A CONTROL APPARATUS FOR AUTOMATICALLY CONTROLLING POLYMERIC INTRINSIC VISCOSITY OF THE FIBER-FORMING POLYETHYLENE TEREPHTHALATE POLYESTER DURING ITS POLYCONDENSING REACTION STAGES, COMPRISING: A. A MINI-COMPUTER, THE CONFIGURATION OF WHICH CONSIST OF A CENTRAL PROCESSOR, A MULTIPLE WORD DISK, A TELETYPE, ANALOG INPUTS, ANALOG OUTPUTS, A REAL TIME CLOCK, CONTACT CLOSURES AND A WATCHDOG TIMER, B. FEEDING AND STORING MEANS FOR FEEDING AND STORING AN ANTICIPATORY CONTROL PROGRAM IN SAID MINICOMPUTER, C. GENERATING MEANS FOR GENERATING SAMPLED DATA INPUTS FROM EACH REACTOR OF PRESSURE, AGITATOR SPEED, INLET AND OUTLET MELT VISCOSITY, INLET AND OUTLET TEMPERATURE, AND PUMP SPEED, D. GENERATING MEANS FOR GENERATING ANALOG SAMPLED INPUTS OF PHYSICAL REPRESENTATIONS OF REACTOR PRESSURE, AGITATOR SPEED, INLET AND OUTLET MELT VISCOSITY, INLET AND OUTLET TEMPERATURE, AND PUMP SPEED, E. STORING MEANS FOR STORING SAID ANALOG SAMPLED INPUT, F. PROCESSING MEANS FOR PROCESING SAID ANALOG SAMPLED INPUTS BY RELATING SAID SAMPLED INPUTS TO SAID ANTICIPATORY CONTROL PROGRAM, AND G. CONTROLLING MEANS FOR CONTROLLING SAID POLYMER INTRINSIC VISCOSITY DURING ITS POLYCONDENSING REACTION STAGES WITHIN PREDETERMINED LIMITS OF SAID ANTICIPATORY CONTROL PROGRAM, THE INTRINSIC VISCOSITY OF THE FIBER-FORMING POLYESTER BEING CONTROLLED WITHIN $ 0.005 UNITS.
 2. The control apparatus of claim 1 wherein the intrinsic viscosity of the polyester is maintained at 0.91 + or -0.005. 